1. Field of the Invention
The present invention relates to an image pickup apparatus such as a video camera.
2. Description of the Related Art
In conventional image pickup apparatus such as video cameras, one known technique of automatic white balance adjustment is to perform feedback control such that, for example, color-difference signals become zero.
Under usual conditions where the image of an object is being picked up continuously, a state of illumination onto the object correctly reflects the image pickup operation. However, in some cases, a state of illumination onto an object cannot be identified. Such a problem occurs for example in a certain time period just after the power has been turned on. In this case, the white extraction should be performed over a wide range since there are various possibilities regarding the type of light source illuminating the object. The expansion of the white extracting range for a certain time period after an image pickup operation has been started causes an increase in time required to correctly adjust the white balance.